PMA Entrance Exam key terms

A whole number with no fractional or decimal part, including positive numbers, negative numbers, and zero. Examples are 7, -3, and 0, but not 2.5 or 1/2.

A whole number greater than 1 whose only positive divisors are 1 and itself. Examples include 2, 3, 5, 7, and 11; 1 and 9 are not prime.

The largest whole number that divides two or more given numbers without a remainder. For 12 and 18, the factors shared are 1, 2, 3, and 6, so the answer is 6.

The smallest positive number that is a multiple of two or more given numbers. For 4 and 6, the multiples are 4, 8, 12 and 6, 12, 18, so the answer is 12.

A number written as one quantity divided by another, such as 3/4, where the bottom number shows how many equal parts make a whole and the top shows how many are taken.

A fraction or ratio expressed as a part of 100, written with the percent sign. For example, 25% means 25 out of every 100, which equals the fraction 1/4 and the decimal 0.25.

A comparison of two quantities by division, often written with a colon. A ratio of 3:5 means the first amount is three parts for every five parts of the second.

An equation stating that two ratios are equal, such as 2/3 = 8/12. In a proportion the cross products are equal, which allows an unknown value to be solved.

The distance of a number from zero on the number line, always zero or positive. The absolute value of both 6 and -6 is 6, written as |6| = 6 and |-6| = 6.

A mathematical statement comparing two expressions that are not necessarily equal, using symbols such as < (less than), > (greater than), ≤ (at most), or ≥ (at least).

A letter or symbol that stands for an unknown or changing number in an expression or equation. In 3x + 5 = 20, the letter x is the variable to be solved.

A combination of numbers, variables, and operation signs without an equals sign, such as 4y - 7. It can be simplified or evaluated but not solved as an equation.

A mathematical sentence stating that two expressions are equal, joined by an equals sign. Solving it means finding the value of the variable that makes the statement true.

The total distance around the outside edge of a closed flat shape. For a rectangle it equals twice the length plus twice the width; for a circle it is called the circumference.

The amount of flat surface enclosed by a shape, measured in square units. A rectangle's area is length times width, and a triangle's area is half the base times the height.

The amount of three-dimensional space a solid occupies, measured in cubic units. For a rectangular box it equals length times width times height.

The arithmetic average of a set of numbers, found by adding all the values and dividing by how many there are. The mean of 2, 4, and 9 is 15 divided by 3, or 5.

The middle value in a set of numbers arranged in order. If there is an even count, it is the mean of the two middle values; in 3, 7, 9, 12 the median is 8.

The value that appears most often in a set of numbers. In the set 4, 5, 5, 8, 9, the mode is 5; a set may have no mode or more than one.

A number from 0 to 1 describing how likely an event is, found by dividing favorable outcomes by total equally likely outcomes. A fair coin landing heads has probability 1/2.

A word that has the same or nearly the same meaning as another word in the same language, such as big and large or begin and start.

A word that means the opposite of another word, such as hot and cold, or expand and contract. Antonym questions ask you to pick the word most nearly opposite in meaning.

A comparison showing a relationship between two pairs of words, written as A is to B as C is to D. The two pairs must share the same logical connection, such as part to whole.

Information in the words and sentences surrounding an unfamiliar word that helps reveal its meaning, such as a definition, example, contrast, or restatement given nearby.

A reasonable conclusion drawn from evidence and reasoning rather than stated directly. Readers combine clues in the text with their own knowledge to infer what is implied.

The central point or most important message a passage conveys about its topic. Supporting details explain, illustrate, or prove the main idea, which is often stated in a topic sentence.

A specific fact, example, statistic, or reason that explains or strengthens the main idea of a passage. Details answer questions such as who, what, when, where, or why.

The reason a writer creates a text, usually to inform, persuade, entertain, or explain. Recognizing the purpose helps a reader judge the tone and reliability of the passage.

The writer's attitude toward the subject or audience, revealed through word choice and sentence style. Tone may be serious, humorous, critical, sympathetic, or neutral.

The grammar rule that a verb must match its subject in number and person. A singular subject takes a singular verb, as in she runs, while a plural subject takes a plural verb.

The noun or noun phrase that a pronoun refers to in a sentence. In the sentence Maria lost her keys, the antecedent of her is Maria, and agreement in number matters.

The form of a verb that shows when an action occurs, such as past, present, or future. Consistent tense keeps a sentence or paragraph clear and grammatically correct.

A word, phrase, or clause that describes or limits another word. A misplaced modifier is placed too far from the word it describes, producing confusing or unintended meaning.

A testable, educated prediction about the outcome of an experiment, often written as an if-then statement. It must be supported or rejected by evidence collected during testing.

A test in which all conditions are kept the same except the one factor being changed, so that results can be attributed to that factor alone.

The process by which green plants use sunlight, water, and carbon dioxide to make sugar and release oxygen. It occurs mainly in the leaves, inside structures called chloroplasts.

The smallest unit of life that can carry out all basic life processes. Some organisms consist of one cell, while plants and animals are made of many specialized cells.

A community of living organisms interacting with one another and with their nonliving surroundings, such as soil, water, and air, in a particular area.

An ordered arrangement of shapes, numbers, or symbols that follows a rule. Finding the pattern means identifying how each item changes to predict the next one.

A repeated or regular arrangement of elements governed by a rule, such as alternating colors or increasing counts. Recognizing the rule lets you predict missing items.

A turn of a figure around a fixed point, described by direction and angle, such as 90 degrees clockwise. The shape keeps its size and form but changes orientation.

A flip of a figure over a line, producing a mirror image. The reflected shape is the same size but faces the opposite direction across the line of symmetry.

A balanced property in which one half of a figure matches the other half when folded along a line or turned around a point. The fold line is called the line of symmetry.